1. O
CH3 – CH2 – CH2 – C – OH
HO – CH3
butanoic acid
methanol
CH3 – CH2 – CH2 – C – O O H
H2O HO
– CH3
methyl butanoate
condensation occurs
water eliminated

2. O H
CH3 – CH2 – CH2 – C – OH
H – N – CH3
butanoic acid
methanamine
CH3 – CH2 – CH2 – C – O H O
H2O H H
– N – CH3
N-methyl butanamide
condensation occurs
water eliminated

3. carboxylic acid group
amine group
– CH2 – CH2 – C – N – CH – N – C – CH2 – CH2 – C – O H
CH3
– N – CH – N – C – CH2 – CH2 – C – N – CH – O H
CH3 OH H
H2O
hydrolysis occurs
(amide breaks)